CN107436535B

CN107436535B - Photosensitive resin composition, dry film, cured product and printed wiring board

Info

Publication number: CN107436535B
Application number: CN201710385807.5A
Authority: CN
Inventors: 峰岸昌司
Original assignee: Taiyo Ink Mfg Co Ltd
Current assignee: Taiyo Holdings Co Ltd
Priority date: 2016-05-26
Filing date: 2017-05-26
Publication date: 2022-06-10
Anticipated expiration: 2037-05-26
Also published as: CN107436535A

Abstract

The invention provides a photosensitive resin composition, a dry film, a cured product and a printed circuit board, in particular to a photosensitive resin composition which has excellent resolution, excellent chemical gold plating resistance and chemical tin plating resistance of the cured product and is not easy to generate out-gassing; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and a printed wiring board having the cured product. The photosensitive resin composition is characterized by containing (A) a carboxyl group-containing resin having an aromatic ring, (B) a photopolymerization initiator and (C) a compound having an ethylenically unsaturated double bond, and containing a compound represented by the following general formula (1) as the photopolymerization initiator (B). (in the general formula (1), R represents a group having an aromatic skeleton or an aliphatic skeleton, and R²Represents a hydrogen atom or an alkyl group, R³Represents an organic group containing a C3-20 cycloalkyl group, R⁴Represents a hydrogen atom, an alkyl group or an aryl group. )

Description

Photosensitive resin composition, dry film, cured product and printed circuit board

Technical Field

The invention relates to a photosensitive resin composition, a dry film, a cured product and a printed circuit board.

Background

In recent years, with the rapid development of semiconductor components, electronic devices tend to be small and lightweight, have high performance, and have multiple functions. In response to this tendency, printed circuit boards have been also being made higher in density and surface mounting of components has been advanced. In the production of high-density printed wiring boards, photosensitive compositions are generally used for forming cured films such as solder resists, and dry film-type compositions and liquid compositions have been developed. Among them, in view of environmental problems, an alkali development type photosensitive composition using a dilute alkali aqueous solution as a developer has become the mainstream, and several composition systems have been proposed (for example, patent documents 1 and 2).

In recent years, in the field of printed wiring boards, thinning and miniaturization of substrates have been accelerated, and high resolution has been required for cured coatings such as solder resists.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 7-15119 (claims)

Patent document 2: japanese laid-open patent publication No. 2002-162736 (claims)

Disclosure of Invention

Problems to be solved by the invention

In the manufacturing process of the printed wiring board, after forming a cured coating such as a solder resist, gold plating or tin plating may be performed in order to perform surface treatment of the conductor pattern, form terminals for printing contact, form pads, and the like. Since no current or lead plating is required for gold plating or tin plating, electroless gold plating or electroless tin plating is often used. However, the plating solution in the electroless gold plating treatment and the electroless tin plating treatment is immersed in the cured coating, and there is a problem that the adhesion of the cured coating is reduced. In particular, the more the cured film is highly refined, the more the adhesion is likely to be reduced by immersion of the plating solution, and therefore, it is difficult to form a highly refined cured film having excellent electroless gold plating resistance and electroless tin plating resistance.

Further, in the case where the photosensitive resin composition is subjected to photocuring, thereafter, thermal curing as needed, or soldering at the time of mounting, there is a problem that a content component such as a photopolymerization initiator volatilizes and vaporizes, and contaminates the surroundings, so-called out gas (out gas). In particular, when soldering is performed during mounting, the solder is exposed to a high temperature of 200 ℃ or higher, and therefore contamination by outgassing is likely to occur.

Accordingly, an object of the present invention is to provide a photosensitive resin composition which is excellent in resolution, electroless gold plating resistance and electroless tin plating resistance of a cured product, and is less likely to generate outgas; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and a printed wiring board having the cured product.

Means for solving the problems

The present inventors have conducted intensive studies in view of the above circumstances, and as a result, have found that: the present inventors have completed the present invention by solving the above problems by blending a carboxyl group-containing resin having an aromatic ring, a photopolymerization initiator having a specific structure, and a compound having an ethylenically unsaturated double bond.

That is, the photosensitive resin composition of the present invention is characterized by containing (a) a carboxyl group-containing resin having an aromatic ring, (B) a photopolymerization initiator, and (C) a compound having an ethylenically unsaturated double bond, and containing a compound represented by the following general formula (1) as the photopolymerization initiator (B).

(in the general formula (1), R represents a group having an aromatic skeleton or an aliphatic skeleton, and R²Represents a hydrogen atom or an alkyl group, R³Represents an organic group containing a C3-20 cycloalkyl group, R⁴Represents a hydrogen atom, an alkyl group or an aryl group. )

In the photosensitive resin composition of the present invention, the compound (C) having an ethylenically unsaturated double bond preferably has 2 or more ethylenically unsaturated double bonds.

In the photosensitive resin composition of the present invention, the weight average molecular weight of the compound (C) having an ethylenically unsaturated double bond is preferably 250 or more and less than 1500.

In the photosensitive resin composition of the present invention, the compound (C) having an ethylenically unsaturated double bond preferably does not have a phenolic hydroxyl group, a thiol group, or a carboxyl group.

The photosensitive resin composition of the present invention preferably further contains (D) a thermosetting component.

In the photosensitive resin composition of the present invention, the thermosetting component (D) is preferably at least one of a solid epoxy resin which is solid at 40 ℃ and a semi-solid epoxy resin which is solid at 20 ℃ and liquid at 40 ℃.

The photosensitive resin composition of the present invention is preferably used for forming at least either one of a solder resist and an interlayer insulating material.

The dry film of the present invention is characterized by having a resin layer obtained by applying the photosensitive resin composition to a film and drying the film.

The cured product of the present invention is obtained by curing the photosensitive resin composition or the resin layer of the dry film.

The printed wiring board of the present invention is characterized by having the cured product.

ADVANTAGEOUS EFFECTS OF INVENTION

The invention provides a photosensitive resin composition which has excellent resolution, excellent chemical gold plating resistance and chemical tin plating resistance of a cured product and is not easy to generate out-gassing; a dry film having a resin layer obtained from the composition; a cured product of the composition or the resin layer of the dry film; and a printed wiring board having the cured product.

Detailed Description

The components of the photosensitive resin composition of the present invention are explained below.

[ (A) carboxyl group-containing resin having aromatic Ring ]

The photosensitive resin composition of the present invention contains (a) a carboxyl group-containing resin having an aromatic ring (hereinafter, also referred to as "(a) carboxyl group-containing resin"). By containing the carboxyl group-containing resin, an alkali-developable photosensitive resin composition can be produced. The carboxyl group-containing resin (a) is not particularly limited, and a known carboxyl group-containing resin used in photosensitive resin compositions for solder resists and interlayer insulating materials can be used as long as it has an aromatic ring. From the viewpoint of photocurability and development resistance, a carboxyl group-containing resin having an ethylenically unsaturated bond in the molecule in addition to a carboxyl group and an aromatic ring, or having no ethylenically unsaturated double bond, is preferable. As the ethylenically unsaturated double bond, unsaturated double bonds derived from acrylic acid or methacrylic acid or their derivatives are preferred. In the present specification, the term (meth) acrylate refers to a general term of acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

(A) The carboxyl group-containing resin can be synthesized by using a compound having an aromatic ring as a raw material. For example, the carboxyl group-containing resin (a) may be synthesized not only when a carboxyl group-containing resin synthesized using a compound having a phenolic hydroxyl group as a starting material, such as (10) and (11) described later, but also when any of various raw materials, such as an unsaturated carboxylic acid, an unsaturated group-containing compound, a diisocyanate, a diol compound, an epoxy resin, and an acid anhydride, used for synthesizing a carboxyl group-containing resin, such as (1) described later, has an aromatic ring.

Specific examples of the carboxyl group-containing resin (a) include the carboxyl group-containing resins (oligomers and polymers) of (1) to (13), but the present invention is not limited thereto. As described above, any raw material used for synthesis may have an aromatic ring.

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α -methylstyrene, a lower alkyl (meth) acrylate, or isobutylene.

(2) The carboxyl group-containing polyurethane resin is obtained by addition polymerization of a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic diisocyanate, a carboxyl group-containing diol compound such as dimethylolpropionic acid or dimethylolbutyric acid, and a diol compound such as a polycarbonate-based polyol, a polyether-based polyol, a polyester-based polyol, a polyolefin-based polyol, an acrylic polyol, a bisphenol a-based alkylene oxide adduct diol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) A carboxyl group-containing urethane resin obtained by addition polymerization of a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic diisocyanate with a diol compound such as a polycarbonate polyol, a polyether polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol a alkylene oxide adduct diol, or a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group, and reacting the terminal of the urethane resin with an acid anhydride.

(4) The carboxyl group-containing polyurethane resin is obtained by addition polymerization of a diisocyanate, a (meth) acrylate of a 2-functional epoxy resin such as a bisphenol a epoxy resin, a hydrogenated bisphenol a epoxy resin, a bisphenol F epoxy resin, a bisphenol S epoxy resin, a bixylenol epoxy resin, a diphenol epoxy resin, or the like, or a modified product of a partial acid anhydride thereof, a carboxyl group-containing diol compound, and a diol compound.

(5) The carboxyl group-containing urethane resin obtained by adding a compound having 1 hydroxyl group and 1 or more (meth) acryloyl groups in the molecule, such as hydroxyalkyl (meth) acrylate, to the synthesis of the resin of the above (2) or (4) and performing terminal (meth) acryloyl group.

(6) The carboxyl group-containing polyurethane resin is obtained by adding a compound having 1 isocyanate group and 1 or more (meth) acryloyl groups in a molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, to the synthesis of the resin of the above (2) or (4) to carry out terminal (meth) acrylation.

(7) A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, or the like to a hydroxyl group present in a side chain.

(8) A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a 2-functional epoxy resin with (meth) acrylic acid using epichlorohydrin and adding a dibasic acid anhydride to the resulting hydroxyl group.

(9) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid and adding a dibasic acid anhydride to the primary hydroxyl group formed.

(10) A carboxyl group-containing resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in 1 molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid and reacting the obtained reaction product with a polybasic acid anhydride.

(11) A carboxyl group-containing resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in 1 molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate with an unsaturated group-containing monocarboxylic acid and reacting the obtained reaction product with a polybasic acid anhydride.

(12) A carboxyl group-containing resin obtained by reacting an epoxy compound having a plurality of epoxy groups in 1 molecule, a compound having at least 1 alcoholic hydroxyl group and 1 phenolic hydroxyl group in 1 molecule such as p-hydroxyphenylethanol, and an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid, and reacting the alcoholic hydroxyl group of the reaction product obtained with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic anhydride.

(13) A carboxyl group-containing resin obtained by further adding a compound having one epoxy group and one or more (meth) acryloyl groups in a molecule, such as glycidyl (meth) acrylate or α -methylglycidyl (meth) acrylate, to the carboxyl group-containing resin described in (1) to (12) above.

The carboxyl group-containing resin (a) is preferably a resin obtained by using a phenol compound as a starting material, as in (10) and (11) of the above-mentioned carboxyl group-containing resins, because the solder resist film formed can obtain high reliability.

(A) The acid value of the carboxyl group-containing resin is preferably in the range of 20 to 200mgKOH/g, more preferably in the range of 40 to 180 mgKOH/g. When the content is in the range of 20 to 200mgKOH/g, the dried coating film obtained by the alkali aqueous solution has good releasability and printability, and is less likely to cause sagging upon drying. Since the carboxyl group-containing resin (a) has a plurality of carboxyl groups in the side chain of the main chain polymer, development can be performed with a dilute aqueous alkali solution.

(A) The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, and is preferably in the range of 2000 to 150000. Within this range, the non-stick property is good, the moisture resistance of the coating film after exposure is good, and the film loss is less likely to occur during development. When the weight average molecular weight is within the above range, the printability and the heat resistance of the cured film are improved. More preferably 5000 to 100000. The weight average molecular weight can be determined by gel permeation chromatography.

The photosensitive resin composition of the present invention may contain an alkali-soluble resin other than the carboxyl group-containing resin (a) within a range not to impair the effects of the present invention.

[ (B) photopolymerization initiator ]

In the present invention, a compound represented by the following general formula (1) is used as the photopolymerization initiator (B).

Here, R may be a group containing an aromatic skeleton or an aliphatic skeleton, and the aromatic skeleton may have 1 or 2 or more aromatic groups such as phenyl groups, and the aliphatic skeleton may be a chain or ring. In addition, R may have an oxime ester skeleton, that is, (B) the photopolymerization initiator may be an oxime ester dimer.

R²The alkyl group which can be selected is preferably a C1-12, more preferably a C1-6, and further preferably a C1-3.

R³The cycloalkyl group in the optional cycloalkyl group having 3 to 20 carbon atoms is preferably 3 to 10 carbon atoms, more preferably 3 to 7 carbon atoms. The cycloalkyl group is more preferably a cyclopentyl group. The organic group containing a cycloalkyl group is preferably a cycloalkylalkyl group, and is preferably a cycloalkylalkyl group composed of a cycloalkyl group and an alkyl group having 1 to 12 carbon atoms (preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms), such as a cycloalkylmethyl group, a cycloalkylethyl group, or a cycloalkylpropyl group.

R⁴The alkyl group which can be selected is preferably a C1-12, more preferably a C1-6, and further preferably a C1-3.

R⁴The aryl group which can be selected is preferably C6-21.

In the present invention, particularly by (B) the photopolymerization initiator has a carbazole skeleton, an oxime ester skeleton, and as R³The organic group containing a cycloalkyl group having 3 to 20 carbon atoms can provide a photosensitive resin composition which is excellent in resolution, electroless gold plating resistance and electroless tin plating resistance of a cured product, and is less likely to generate outgas. (B) The photopolymerization initiator is preferably a compound represented by the following general formula (1A).

(in the above general formula (1A), R¹And R²Each independently represents a hydrogen atom or an alkyl group, R³Represents an organic group containing a C3-20 cycloalkyl group, R⁴Represents a hydrogen atom, an alkyl group or an aryl group. )

R¹The alkyl group which can be selected is preferably a C1-12, more preferably a C1-6, and further preferably a C1-3. For R²～R⁴The groups which can be selected are the same as those of the above general formula (1).

Specific examples of the compound represented by the general formula (1) include, but are not limited to, the following chemical formulas. Specific examples of the following chemical formula include: TR-PBG-304 manufactured by Changzhou powerful New electronic Material Co.

(B) The amount of the photopolymerization initiator to be added is preferably 0.01 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin (a). When the amount is 0.01 parts by mass or more, electroless gold plating resistance, electroless tin plating resistance and dry-to-touch property become better, and when the amount is 20 parts by mass or less, dry-to-touch property becomes better, and the occurrence of outgas becomes less likely.

The photosensitive resin composition of the present invention may contain a photopolymerization initiator other than the photopolymerization initiator (B) within a range not impairing the effects of the present invention.

[ (C) Compounds having an ethylenically unsaturated double bond ]

The photosensitive resin composition of the present invention contains (C) a compound having an ethylenically unsaturated double bond. As the compound (C) having an ethylenically unsaturated double bond, a photopolymerizable oligomer, a photopolymerizable vinyl monomer, and the like, which are known and commonly used photocurable monomers, can be used. (C) The compound having an ethylenically unsaturated double bond can be photocured by irradiation with active energy rays, and the photosensitive resin composition of the invention is rendered insoluble or insolubilized by an alkali aqueous solution. Further, by containing (C) the compound having an ethylenically unsaturated double bond, curability becomes good, and soldering heat resistance is improved.

Examples of the compound used as the compound having an ethylenically unsaturated double bond (C) include: conventional polyester (meth) acrylates, polyether (meth) acrylates, urethane (meth) acrylates, carbonate (meth) acrylates, epoxy (meth) acrylates, and the like are known. Specifically, the following may be suitably selected and used: hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; acrylamides such as N, N-dimethylacrylamide, N-methylolacrylamide, and N, N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; polyvalent acrylates such as polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol and trishydroxyethyl isocyanurate, ethylene oxide adducts, propylene oxide adducts and epsilon-caprolactone adducts thereof; polyacrylates such as phenoxy acrylates, bisphenol a diacrylates, and ethylene oxide adducts and propylene oxide adducts of these phenols; glycidyl ether polyacrylates such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; not limited to the above compounds, and at least 1 kind of the acrylic esters and melamine acrylates obtained by direct acrylation of a polyol such as polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, or polyester polyol, or urethane acrylation via diisocyanate, and the methacrylic esters corresponding to the above acrylates.

Epoxy acrylate resins obtained by reacting a polyfunctional epoxy resin such as a cresol novolak type epoxy resin with acrylic acid; and an epoxy urethane acrylate compound obtained by further reacting a hemiurethane compound formed from a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate with the hydroxy group of the epoxy acrylate resin, as (C) a compound having an ethylenically unsaturated double bond. The epoxy acrylate resin can improve photocurability without lowering finger-touch dryness.

The compound having an ethylenically unsaturated double bond (C) is preferably polyfunctional, that is, has 2 or more ethylenically unsaturated double bonds, in order to more favorably suppress the out-gassing and improve the finger-touch-drying property. The number of the ethylenically unsaturated double bonds is more preferably 3 to 15, and still more preferably 5 to 12. The weight average molecular weight of the compound (C) having an ethylenically unsaturated double bond is preferably 250 or more and less than 1500 for the same reason as described above. More preferably 300 to 900, and still more preferably 300 to 600. The compound (C) having an ethylenically unsaturated double bond is preferably a compound modified with an alkylene oxide such as ethylene oxide, for example, trimethylolpropane EO-modified triacrylate, more preferably- (OC) for the same reason as described above_mH_2m)_nA structure (n and m are integers of 1 or more; n is preferably 1 to 4, more preferably 1 to 2; and m is preferably 2 to 3).

(C) The compound having an ethylenically unsaturated double bond preferably does not have a phenolic hydroxyl group, a thiol group, and a carboxyl group from the viewpoint of promoting photocurability.

(C) The amount of the compound having an ethylenically unsaturated double bond is preferably 5 to 100 parts by mass, more preferably 5 to 70 parts by mass, per 100 parts by mass of the carboxyl group-containing resin (a). By setting the amount to 5 parts by mass or more, the photocurability of the photosensitive resin composition is improved. Further, the coating film hardness can be improved by setting the amount to 100 parts by mass or less.

[ (D) thermosetting component ]

The photosensitive resin composition of the present invention preferably contains a thermosetting component. As the thermosetting component, a known and conventional thermosetting resin such as an isocyanate compound, a blocked isocyanate compound, an amino resin, a maleimide compound, a benzoxazine resin, a carbodiimide resin, a cyclic carbonate compound, a polyfunctional epoxy compound, a polyfunctional oxetane compound, an episulfide resin, or the like can be used. Among these, a preferred thermosetting component is one having at least one of a plurality of cyclic ether groups and cyclic thioether groups (hereinafter simply referred to as cyclic (thio) ether groups) in 1 molecule. These thermosetting components having a cyclic (thio) ether group are commercially available in a wide variety of types, and various properties can be imparted to the thermosetting components depending on their structures.

The thermosetting component having a plurality of cyclic (thio) ether groups in a molecule is a compound having one or two of a plurality of cyclic ether groups having a ternary, quaternary or quinary ring in a molecule, or cyclic thioether groups, and examples thereof include: a compound having a plurality of epoxy groups in a molecule, that is, a polyfunctional epoxy compound; a compound having a plurality of oxetanyl groups in the molecule, i.e., a polyfunctional oxetane compound; and episulfide resins that are compounds having a plurality of thioether groups in the molecule.

As the epoxy compound, known and conventional compounds having 1 or more epoxy groups can be used, and among them, compounds having 2 or more epoxy groups are preferable. Examples thereof include: butyl glycidyl ether, phenyl glycidyl ether, monoepoxy compounds such as glycidyl (meth) acrylate, bisphenol A type epoxy resins, bisphenol S type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, trisphenol methane type epoxy resins, alicyclic epoxy resins, trimethylolpropane polyglycidyl ether, phenyl-1, 3-diglycidyl ether, biphenyl-4, 4' -diglycidyl ether, 1, 6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, sorbitol polyglycidyl ether, tris (2, 3-epoxypropyl) isocyanurate, triglycidyl isocyanurate (2-hydroxyethyl) and other compounds having 2 or more epoxy groups in 1 molecule. They may be used alone or in combination of 2 or more depending on the required characteristics.

As the compound having 2 or more epoxy groups, specifically, there can be mentioned: epoxy resins such as JeR828, JeR834, JeR1001, JeR1004, EPICLON840, EPICLON 850, EPICLON 1050, EPICLON 2055, EPTOTO YD-011, YD-013, YD-127, YD-128, D.E.R.317, D.E.R.331, D.E.R.661, D.E.R.664, Sumi-epoxyESA-011, ESA-014, ELA-115, ELA-128, A.E.R.330, A.E.R.331, A.E.R.661, A.E.R.664 and A.E.R.664 of Sumi-epoxyESA-011; brominated epoxy resins such as jERYL903 manufactured by mitsubishi Chemical corporation, EPICLON 152 manufactured by DIC corporation, EPICLON 165, EPOTOTO YDB-400 and YDB-500 manufactured by new york chemico, d.e.r.542 manufactured by Dow Chemical Japan ltd, Sumi-epoxyESB-400 manufactured by sumitomo Chemical corporation, ESB-700, a.e.r.711 and a.e.r.714 manufactured by ASAHI KASEI E-materials corp; JeR152, JeR154, D.E.N.431, D.E.N.438, EPICLON N-730, EPICLON-770, EPICLON-865, EPTOTO YDCN-701, YDCN-704, EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000, Sumi-epoxyESCN-195-220, YDCN-24, YDCN-700, YDCN-700-2, YDCN-700-3, YDCN-5-YDCN-700, YDCN-700-704, YDCN-700, YDCN-704, YDCN-700, YDCN-3000, YDCN-704, YDCN-100, YDCN-700, YDCN-3000, YDCN-704, YDCN-150, YDCN-700, YDCN-III, and YDCN-III, Novolac type epoxy resins such as EPICLON N-680, N-690 and N-695 (trade name) manufactured by DIC; bisphenol F type epoxy resins such as EPICLON 830 manufactured by DIC corporation, jER807 manufactured by Mitsubishi chemical corporation, EPTOTO YDF-170, YDF-175, YDF-2004 manufactured by Nissan Tekko chemical corporation; hydrogenated bisphenol A type epoxy resins such as EPOTTO ST-2004, ST-2007 and ST-3000 manufactured by Nippon iron-on-gold chemical Co., Ltd; JeR604 manufactured by Mitsubishi chemical corporation, EPOTO YH-434 manufactured by New Nissan Ciscow; glycidyl amine type epoxy resins such as Sumi-epoxyELM-120 available from Sumitomo chemical Co., Ltd; hydantoin type epoxy resins; alicyclic epoxy resins such as celloxide2021 manufactured by Daicel Corporation; trihydroxyphenyl methane type epoxy resins such as YL-933 manufactured by Mitsubishi Chemical corporation, T.E.N. manufactured by Dow Chemical Japan Ltd., EPPN-501, EPPN-502, and the like; a bixylenol-type or biphenol-type epoxy resin such as YL-6056, YX-4000, YL-6121, manufactured by Mitsubishi chemical corporation, or a mixture thereof; bisphenol S type epoxy resins such as EBPS-200 manufactured by Nippon Kabushiki Kaisha, EPX-30 manufactured by ADEKA Kaisha, and EXA-1514 manufactured by DIC Kaisha; bisphenol a novolac type epoxy resins such as jER157S manufactured by mitsubishi chemical corporation; tetrahydroxyphenyl ethane type epoxy resins such as jERYL-931 manufactured by Mitsubishi chemical corporation; heterocyclic epoxy resins such as TEPIC manufactured by Nissan Chemical Industries, Ltd; diglycidyl phthalate resin such as BLEMMER DGT manufactured by japan fat and oil co; tetraglycidyl xylenol ethane resins such as ZX-1063 manufactured by Nippon iron Japan chemical Co., Ltd; naphthyl group-containing epoxy resins such as ESN-190, ESN-360, HP-4032, EXA-4750 and EXA-4700, manufactured by NITRI CORDIX CHEMICAL; epoxy resins having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resins such as CP-50S, CP-50M manufactured by Nippon fat and oil Co., Ltd; further copolymerized epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; CTBN-modified epoxy resins (e.g., YR-102, YR-450, manufactured by Nippon iron-Co., Ltd.); and a trisphenol methane type epoxy resin, but is not limited thereto.

Among them, from the viewpoint of improving the properties such as electroless gold plating resistance and electroless tin plating resistance, a solid epoxy resin which is solid at 40 ℃, a semi-solid epoxy resin which is solid at 20 ℃ and liquid at 40 ℃ are preferable. Examples of the solid epoxy resin which is solid at 40 ℃ include: naphthalene type epoxy resins such as 4-functional naphthalene type epoxy resins and polyfunctional solid epoxy resins having a naphthalene skeleton; epoxides of condensates of phenols with aromatic aldehydes having a phenolic hydroxyl group (triphenol-type epoxy resins); dicyclopentadiene aralkyl type epoxy resins such as a multifunctional solid epoxy resin containing a dicyclopentadiene skeleton; biphenyl aralkyl type epoxy resins such as a biphenyl skeleton-containing polyfunctional solid epoxy resin; a novolac type epoxy resin; a bixylenol-type or biphenyl-type epoxy resin such as YX-4000 manufactured by Mitsubishi chemical corporation, or a mixture thereof; cresol novolak type epoxy resins such as RN-695 available from DIC; heterocyclic epoxy resins such as TEPIC manufactured by Nissan Chemical Industries, Ltd. Particular preference is given to using epoxy resins of the bixylenol type or of the diphenol type or mixtures thereof.

Examples of the semisolid epoxy resin which is solid at 20 ℃ and liquid at 40 ℃ include: bisphenol a type epoxy resin; naphthalene type epoxy resins; phenol novolac type epoxy resins, and the like.

The determination of the liquid state was performed according to the test of the dangerous object and the method of "confirmation of liquid state" attached to province command (No. 1) related to the property.

These epoxy resins may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Next, the oxetane compound will be described. Containing the following general formula (2) (wherein R is⁵A hydrogen atom or an alkyl group having 1 to 6 carbon atoms) may be mentioned: 3-Ethyl-3-hydroxymethyloxetane (OXT-101, manufactured by Toyo Synthesis K.), 3-ethyl-3- (phenoxymethyl) oxetane (OXT-211, manufactured by Toyo Synthesis K.), 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (OXT-212, manufactured by Toyo Synthesis K.), 1, 4-bis { [ (3-ethyl-3-oxetanyl) methoxybutyl group]Methyl } benzene (OXT-121 available from Toyo Synthesis Co., Ltd.), bis (3-ethyl-3-)Oxetanyl methyl) ether (OXT-221 available from Toyo Kabushiki Kaisha). Further, there can be mentioned: and oxetane compounds of phenol novolac type. These oxetane compounds may be used in combination with the above epoxy compounds, or may be used alone.

The amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is preferably in the range of 0.3 to 2.5 equivalents of the cyclic (thio) ether group, more preferably 0.5 to 2.0 equivalents of the cyclic (thio) ether group, based on 1 equivalent of the carboxyl group-containing resin (a) in terms of solid content. When the amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is 0.3 equivalent or more to the cyclic (thio) ether group, the cured film is less likely to have carboxyl groups left, and is excellent in heat resistance, chemical resistance, electrical insulation properties, and the like. On the other hand, when the cyclic (thio) ether group has an equivalent weight of 2.5 or less, the cyclic (thio) ether group having a low molecular weight is less likely to remain in a dried coating film, and the strength of the cured coating film is good.

(inorganic Filler)

The photosensitive resin composition of the present invention preferably contains an inorganic filler, and more preferably contains a surface-treated inorganic filler. Here, the surface treatment of the inorganic filler means a treatment for improving compatibility with the resin component. The surface treatment of the inorganic filler is preferably a surface treatment capable of introducing a curable reactive group to the surface of the inorganic filler.

The inorganic filler is not particularly limited, and known and conventional fillers, for example, inorganic fillers such as silica, crystalline silica, noni silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, and zinc white can be used. Among these, silica is preferable, and spherical silica is more preferable from the viewpoint that the surface area is small and the silica is less likely to become a starting point of a crack due to the stress dispersion in the whole.

The surface-treated inorganic filler may or may not have a curable reactive group on the surface, which reacts with the carboxyl group-containing resin (a) and the curable component. In the present specification, the curable reactive group is not particularly limited as long as it is a group that undergoes a curing reaction with the carboxyl group-containing resin (a) and the curable component, and may be a thermosetting reactive group or a photocurable reactive group. Examples of the photocurable reactive group include: methacrylic group, acrylic group, vinyl group, styryl group, and the like, and examples of the thermosetting reactive group include: epoxy, amino, hydroxyl, carboxyl, isocyanate, imino, oxetanyl, mercapto, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, oxazolinyl, and the like. In addition, the inorganic filler may have 2 or more curable reactive groups.

Among them, epoxy groups, acrylic groups, methacrylic groups, vinyl groups, and styrene groups are preferable because of low reactivity at room temperature (40 ℃ C. or lower) and stability in the composition. Further, an acrylic group, a methacrylic group, and an epoxy group, which have high stability at room temperature but rapidly react upon heating and upon irradiation with ultraviolet rays, are more preferable, and an acrylic group and a methacrylic group, which have high photo radical reactivity, improved photosensitivity of the composition, low hygroscopicity after reaction, and capability of forming a strong chemical bond, are further more preferable. The formation of chemical bonds between (a) the carboxyl group-containing resin, the curable component, and the surface-treated inorganic filler can improve the crack resistance.

The method for introducing the curable reactive group to the surface of the inorganic filler is not particularly limited as long as the introduction is carried out by a known and conventional method, and the surface of the inorganic filler may be treated with a surface treating agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group, or the like.

As the surface treatment of the inorganic filler, a surface treatment based on a coupling agent is preferable. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent, or the like can be used. Among them, a silane coupling agent is preferable.

The silane coupling agent is preferably a silane coupling agent capable of introducing a curing reactive group to the inorganic filler. Examples of the silane coupling agent capable of introducing a thermosetting reactive group as an organic group include: among these, a silane coupling agent having an epoxy group and a silane coupling agent having an amino group are more preferable. The silane coupling agent capable of introducing the photocurable reactive group as an organic group is preferably a silane coupling agent having a vinyl group, a silane coupling agent having a styryl group, a silane coupling agent having a methacrylic group, or a silane coupling agent having an acrylic group, and among these, a silane coupling agent having a methacrylic group is more preferred.

Further, examples of the inorganic filler having no curable reactive group and subjected to surface treatment include: inorganic fillers surface-treated with alumina, and the like.

The inorganic filler subjected to surface treatment may be blended in the photosensitive resin composition of the present invention in a state of being subjected to surface treatment, or the inorganic filler may be subjected to surface treatment by separately blending the inorganic filler subjected to surface treatment with a surface treatment agent, and the inorganic filler subjected to surface treatment in advance is preferably blended in the composition. By compounding the inorganic filler subjected to surface treatment in advance, it is possible to prevent a reduction in crack resistance and the like caused by the surface treatment agent which is not consumed by the surface treatment which may remain when it is compounded separately. When the surface treatment is performed in advance, it is preferable to blend a predispersion obtained by predispersing the surface-treated inorganic filler in a solvent, and more preferably, the predispersion is blended with the composition after predispersing the surface-treated inorganic filler in a solvent, or the predispersion is blended with the composition after sufficiently performing the surface treatment when the surface-untreated inorganic filler is predispersed in a solvent.

When the average particle size of the inorganic filler is 2 μm or less, the embedding property into the fine line portion after lamination is more excellent, and therefore, it is preferable. More preferably 1 μm or less.

The amount of the inorganic filler is preferably 10 to 300 parts by mass, more preferably 20 to 200 parts by mass, in terms of solid content, per 100 parts by mass of the carboxyl group-containing resin (a).

The surface-treated inorganic filler may be used in combination with an inorganic filler that has not been surface-treated.

(coloring agent)

The photosensitive resin composition of the present invention may contain a colorant. As the colorant, conventionally known colorants such as red, blue, green, yellow, white, and black may be used, and any of pigments, dyes, and pigments may be used. Specifically, there may be mentioned: colorants with a color index (c.i.; issued by The Society of Dyers and Colourists) number. Among them, a colorant containing no halogen is preferable from the viewpoint of reducing environmental load and influence on the human body.

Examples of the red colorant include: monoazo systems, disazo systems, azo lake systems, benzimidazolone systems, perylene systems, diketopyrrolopyrrole systems, condensed azo systems, anthraquinone systems, quinacridone systems, and the like. Examples of the blue colorant include phthalocyanine-based colorants and anthraquinone-based colorants, which may be substituted or unsubstituted with metals, and the Pigment-based colorants include compounds classified as pigments (pigments). As the green colorant, phthalocyanine, anthraquinone and perylene, which may be substituted or unsubstituted with metal, are also available. Examples of the yellow colorant include: monoazo systems, disazo systems, condensed azo systems, benzimidazolone systems, isoindolinone systems, anthraquinone systems, and the like. Examples of the white colorant include: titanium oxide such as rutile type and anatase type. Examples of the black coloring agent include: titanium black-based, carbon black-based, graphite-based, iron oxide-based, anthraquinone-based, cobalt oxide-based, copper oxide-based, manganese-based, antimony oxide-based, nickel oxide-based, perylene-based, aniline-based pigments, molybdenum sulfide, bismuth sulfide, and the like. In addition, a colorant such as violet, orange, brown, or the like may be added for adjusting the color tone.

The coloring agent may be used alone in 1 kind or in combination of 2 or more kinds. The amount of the colorant to be blended is not particularly limited, but is preferably 10 parts by mass or less in terms of solid content per 100 parts by mass of the carboxyl group-containing resin (a). More preferably 0.1 to 5 parts by mass.

(organic solvent)

The photosensitive resin composition of the present invention may contain an organic solvent for preparing the composition and adjusting the viscosity when applied to a substrate or a support film. As organic solvents, it is possible to use: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, naphtha and solvent naphtha. These organic solvents may be used alone or in combination of two or more.

(other optional ingredients)

Further, other additives conventionally used in the field of electronic materials may be blended in the photosensitive resin composition of the present invention. Examples of other additives include: a block copolymer, a thermosetting catalyst, a curing agent, a thermal polymerization inhibitor, an ultraviolet absorber, a silane coupling agent, a plasticizer, a flame retardant, an antistatic agent, an anti-aging agent, an antibacterial/antifungal agent, a defoaming agent, a leveling agent, a thickener, an adhesion imparting agent, a thixotropy imparting agent, a photoinitiating auxiliary agent, a sensitizer, a photobase generator, a thermoplastic resin, an elastomer, an organic filler, a mold release agent, a surface treating agent, a dispersant, a dispersing auxiliary agent, a surface modifier, a stabilizer, a phosphor, and the like.

The photosensitive resin composition of the present invention can be used in the form of a dry film or in the form of a liquid. When used in a liquid form, the liquid may be 1-liquid type or 2-liquid type or more. For example, the carboxyl group-containing resin (a) and the photopolymerization initiator (B) may be blended in the same formulation or may be blended in different formulations.

Next, the dry film of the present invention has a resin layer obtained by coating the photosensitive resin composition of the present invention on a carrier film and drying it. In forming a dry film, the photosensitive resin composition of the present invention is first diluted with the above-mentioned organic solvent to adjust the viscosity to an appropriate level, and then coated on a carrier film to a uniform thickness by means of a comma coater (comma coater), a knife coater, a lip coater, a rod coater (rod coater), a squeeze coater (squeze coater), a reverse coater (reverse coater), a transfer roll coater (gravure coater), a spray coater, or the like. Then, the coated composition is dried at a temperature of 40 to 130 ℃ for 1 to 30 minutes, so that a resin layer can be formed. The coating film thickness is not particularly limited, and is usually selected appropriately within a range of 3 to 150 μm, preferably 5 to 60 μm, in terms of the film thickness after drying.

As the carrier film, a plastic film, for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, and is usually appropriately selected within a range of 10 to 150 μm. More preferably in the range of 15 to 130 μm.

After forming a resin layer formed from the photosensitive resin composition of the present invention on a carrier film, a peelable cover film is preferably further laminated on the surface of the resin layer in order to prevent dust and the like from adhering to the surface of the resin layer. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. The cover film may be one having a lower adhesive force between the resin layer and the carrier film when the cover film is peeled.

In the present invention, the photosensitive resin composition of the present invention may be applied to the cover film and dried to form a resin layer, and the carrier film may be laminated on the surface of the resin layer. That is, in the present invention, when a dry film is produced, a carrier film and a cover film may be used as a thin film to which the photosensitive resin composition of the present invention is applied.

The printed wiring board of the present invention has a cured product obtained from the photosensitive resin composition or the resin layer of the dry film of the present invention. As the method for producing the printed wiring board of the present invention, for example, the photosensitive resin composition of the present invention is adjusted to a viscosity suitable for a coating method using the above-mentioned organic solvent, and is coated on a substrate by a method such as dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, and the like, and then the organic solvent contained in the composition is volatilized and dried (temporarily dried) at a temperature of 60 to 100 ℃. In the case of a dry film, a resin layer can be formed on a substrate by laminating the resin layer on the substrate so that the resin layer is in contact with the substrate using a laminator or the like, and then peeling off the carrier film.

Examples of the substrate include, in addition to a printed wiring board and a flexible printed wiring board on which a circuit is formed in advance with copper or the like, a copper-clad laminate of all grades (e.g., FR-4) using a material such as a copper-clad laminate for high-frequency circuits using paper-phenol resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth/nonwoven fabric-epoxy resin, glass cloth/paper-epoxy resin, synthetic fiber-epoxy resin, fluorine resin, polyethylene, polyphenylene oxide (polyphenylene oxide) cyanate ester, or the like, a metal substrate, a polyimide film, a PET film, a polyethylene naphthalate (PEN) film, a glass substrate, a ceramic substrate, a wafer plate, and the like.

The volatilization drying after the application of the photosensitive resin composition of the present invention can be carried out using a hot air circulation type drying oven, an IR oven, a hot plate, a convection oven, or the like (a method of bringing hot air in a drying machine into convection contact using a device having a heat source of an air heating system using steam and a method of blowing the hot air to a support through a nozzle).

After a resin layer is formed on a printed wiring board, the unexposed portion is developed with a dilute alkali aqueous solution (for example, a 0.3 to 3 mass% sodium carbonate aqueous solution) by selectively exposing the resin layer to active energy rays through a photomask having a predetermined pattern formed thereon, thereby forming a pattern of a cured product. Further, the cured product is irradiated with an active energy ray and then cured by heating (for example, at 100 to 220 ℃), or is irradiated with an active energy ray after cured by heating, or is finally cured (completely cured) by only curing by heating, whereby a cured film having excellent properties such as adhesiveness and hardness is formed.

When the photosensitive resin composition of the present invention contains a photobase generator, it is preferably heated before development after exposure, and as a heating condition before development after exposure, for example, it is preferably heated at 60 to 150 ℃ for 1 to 60 minutes.

The exposure machine used for the irradiation with the active energy rays may be a device equipped with a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like and irradiating ultraviolet rays in the range of 350 to 450nm, and a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser beam using CAD data from a computer) may be used. As a lamp light source or a laser light source of the line drawing machine, the maximum wavelength is within the range of 350-450 nm. The exposure amount for forming an image varies depending on the film thickness, etc., and is usually 10 to 1000mJ/cm²Preferably 20 to 800mJ/cm²Within the range of (1).

As the developing method, a dipping method, a rinsing method, a spraying method, a brush coating method, and the like can be used, and as the developer, an alkaline aqueous solution of potassium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, and the like can be used.

The photosensitive resin composition of the present invention can be used not only for forming a pattern of a cured film by a development treatment, but also for forming a pattern of a cured film by an ink-jet method without performing a development treatment.

The photosensitive resin composition of the present invention is suitably used for forming a cured film, more preferably a permanent film, and further preferably a Solder resist, an interlayer insulating material, a marking ink, a cover layer, and a tin Dam (Solder Dam) on a printed wiring board. Further, the photosensitive resin composition of the present invention is excellent in resolution, and therefore, can be suitably used for forming a permanent coating (particularly, solder resist) for a printed wiring board having a fine-pitch wiring pattern, for example, a package substrate, particularly, FC-BGA. In addition, the photosensitive resin composition of the present invention can be used for forming a protective film for a semiconductor wafer.

Examples

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. In the following, all of the "parts" and "%" are based on mass unless otherwise specified.

(Synthesis example 1 Synthesis of carboxyl group-containing resin A-1 having aromatic Ring)

To 600g of diethylene glycol monoethyl ether acetate were added 1070g (number of glycidyl groups (total number of aromatic rings): 5.0 mol) of an o-cresol novolac type epoxy resin (EPICLON N-695 manufactured by DIC Co., Ltd., softening point 95 ℃, epoxy equivalent 214, average number of functional groups 7.6), 360g (5.0 mol) of acrylic acid, and 1.5g of hydroquinone, and the mixture was heated to 100 ℃ and stirred to be dissolved uniformly. Subsequently, 4.3g of triphenylphosphine was added to the solution, and the mixture was heated to 110 ℃ to react for 2 hours. Then, the temperature was raised to 120 ℃ and the reaction was further carried out for 12 hours. 415g of aromatic hydrocarbon (Solvesso150) and 456.0g (3.0 mol) of tetrahydrophthalic anhydride were charged into the obtained reaction solution, and the mixture was reacted at 110 ℃ for 4 hours, followed by cooling to obtain a carboxyl group-containing resin solution A-1 having an aromatic ring and a solid acid value of 89mgKOH/g and a solid content of 65 mass%.

(Synthesis example 2 Synthesis of carboxyl group-containing resin A-2 having aromatic Ring)

119.4 parts of novolak-type cresol resin (Shonol CRG951, available from Showa Denko K.K., OH equivalent: 119.4), 1.19 parts of potassium hydroxide, and 119.4 parts of toluene were charged into an autoclave equipped with a thermometer, an alkylene oxide introducing device with a nitrogen introducing device, and a stirring device, and the inside of the system was replaced with nitrogen while stirring, thereby heating and raising the temperature. Then, 63.8 parts of propylene oxide was slowly added dropwise thereto at 125 to 132 ℃ at 0 to 4.8kg/cm²The reaction was allowed to proceed for 16 hours. Then, the reaction solution was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to the reaction solution and mixed to neutralize potassium hydroxide, thereby obtaining a nonvolatile matter of 62.1% and a hydroxyl value182.2 g/eq.propylene oxide reaction solution of novolak-type cresol resin. This is the average addition of 1.08 moles of alkylene oxide per 1 equivalent of phenolic hydroxyl group.

293.0 parts of the obtained novolak-type cresol resin alkylene oxide reaction solution, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 part of methylhydroquinone, and 252.9 parts of toluene were charged into a reactor equipped with a stirrer, a thermometer, and an air-blowing tube, and air was blown at a rate of 10 ml/min, and the mixture was reacted at 110 ℃ for 12 hours while stirring.

As for the water produced by the reaction, 12.6 parts of water was distilled off as an azeotropic mixture thereof with toluene. Thereafter, the reaction solution was cooled to room temperature, neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, the toluene was replaced with 118.1 parts of diethylene glycol monoethyl ether acetate (carbitol acetate) by an evaporator and distilled off to obtain a novolak-type acrylate resin solution.

Next, 332.5 parts of the obtained novolak type acrylate resin solution and 1.22 parts of triphenylphosphine were put into a reactor equipped with a stirrer, a thermometer and an air blowing tube, air was blown at a rate of 10 ml/min, 60.8 parts of tetrahydrophthalic anhydride was slowly added with stirring, and the mixture was reacted at 95 to 101 ℃ for 6 hours, followed by cooling to obtain a carboxyl group-containing resin solution a-2 having an aromatic ring and a solid acid value of 88mgKOH/g and a solid content of 70.9 mass%.

(Synthesis example 3 Synthesis of carboxyl group-containing resin A-3 having aromatic Ring)

42 parts by mass of methacrylic acid, 43 parts by mass of methyl methacrylate, 35 parts by mass of styrene, 35 parts by mass of benzyl acrylate, 100 parts by mass of carbitol acetate, 0.5 part by mass of lauryl mercaptan and 4 parts by mass of azobisisobutyronitrile were charged into a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen replacement and a stirrer, and the mixture was heated at 75 ℃ for 5 hours under a nitrogen stream to carry out polymerization reaction, thereby obtaining a copolymer solution (solid content concentration 50% by mass). 0.05 part by mass of hydroquinone, 23 parts by mass of glycidyl methacrylate and 2.0 parts by mass of dimethylbenzylamine were added to the copolymer solution to conduct addition reaction at 80 ℃ for 24 hours, and then 35 parts by mass of carbitol acetate was added to obtain a carboxyl group-containing resin solution A-3 having an aromatic ring with a solid content of 50.0 mass%.

(Synthesis example 4 Synthesis of carboxyl group-containing resin)

In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, 325.0 parts by mass of dipropylene glycol monomethyl ether as a solvent was heated to 110 ℃, a mixture of 174.0 parts by mass of methacrylic acid, 174.0 parts by mass of epsilon-caprolactone-modified methacrylic acid (average molecular weight 314), 77.0 parts by mass of methyl methacrylate, 222.0 parts by mass of dipropylene glycol monomethyl ether and 12.0 parts by mass of t-butylperoxy 2-ethylhexanoate (Perbutyl O manufactured by nippon oil & fat co., ltd.) as a polymerization catalyst was added dropwise over 3 hours, and the mixture was further stirred at 110 ℃ for 3 hours to deactivate the polymerization catalyst, thereby obtaining a resin solution. The resin solution was cooled, and then CYCLOMER M100289.0 parts by mass, triphenylphosphine 3.0 parts by mass, and hydroquinone monomethyl ether 1.3 parts by mass, manufactured by Daicel Corporation, were added thereto, and the mixture was heated to 100 ℃ and stirred to perform a ring-opening addition reaction of an epoxy group, thereby obtaining a carboxyl group-containing resin solution having a solid acid value of 79.8mgKOH/g and a solid content of 45.5 mass%.

Preparation example 1 preparation of Filler solvent Dispersion product alpha

Spherical silica (SFP-30M manufactured by ECO K., having an average particle diameter d50 of 0.7 μ M)70g, PMA (propylene glycol monomethyl ether acetate) 28g as a solvent, and KBE-5022.0 g as a silane coupling agent having a methacrylic acid group, manufactured by Shin-Etsu Chemical Co., Ltd.) were uniformly dispersed to obtain a filler solvent dispersion α.

Examples 1 to 6 and comparative examples 1 to 3

The photosensitive resin compositions were prepared by mixing the components in the proportions (parts by mass) shown in table 1 according to the formulations shown in table 1 below, premixing the components with a mixer, and kneading the mixture with a three-roll mill.

(resolution)

The photosensitive resin compositions of examples and comparative examples were formed in a dry film thicknessThe whole surface of the substrate was coated with a 20 μm pattern by screen printing to a thickness of 1.6mm on a copper-filled FR-4 substrate, dried at 80 ℃ for 30 minutes, and naturally cooled to room temperature. On the substrate, a non-contact (off contact) exposure apparatus equipped with an ultra-high pressure mercury lamp (short arc lamp 5KW) was used, exposure was performed at the above-mentioned optimum exposure using a negative pattern having a line width of 100 μm of a light shielding portion, and 1 mass% Na of 30 ℃ was added₂CO₃The aqueous solution was developed at a jet pressure of 0.2MPa for 120 seconds and thermally cured at 150 ℃ for 60 minutes to obtain an evaluation sample. The line width of the blank of the evaluation sample obtained was measured by an optical microscope and evaluated according to the following evaluation criteria.

Very good: the line width of the blank is less than 50 μm.

O: the line width of the blank is less than 100 μm.

X: the line width of the blank is 100 μm or more.

(conditions for producing substrate for evaluation of electroless gold plating resistance, electroless tin plating resistance and chemical resistance)

The photosensitive resin compositions of examples and comparative examples were applied to the FR-4 material over the entire surface by screen printing, dried in a hot air circulation type drying oven at 80 ℃ for 30 minutes, and naturally cooled to room temperature. The substrate was exposed to light through a negative mask at an optimum exposure, developed with a 1 mass% aqueous solution of sodium carbonate at 30 ℃ under a spray pressure of 0.2MPa for 90 seconds, and washed with water to obtain a developed substrate. Further, after-curing was performed at 150 ℃ for 60 minutes to obtain a substrate.

The optimum exposure amount is as follows. The dried coated substrate was exposed to light using an exposure apparatus equipped with a high-pressure mercury lamp (short arc lamp) via a stepwise exposure meter (Kodak No.2), and developed (30 ℃, 0.2MPa, 1 wt% Na)₂CO₃Aqueous solution) was used for 60 seconds, and the exposure amount of the pattern of the stepwise exposure meter remaining at 7 steps was used as the optimum exposure amount.

(chemical plating resistance)

The evaluation substrate prepared under the above substrate preparation conditions was immersed in an acidic degreasing solution (20 vol% aqueous solution of METEX L-5B, manufactured by Nippon MacDermid co., ltd.) at 30 ℃ for 3 minutes, then washed with water, then immersed in a 14.4 wt% aqueous ammonium persulfate solution for 3 minutes at room temperature, washed with water, and further immersed in a 10 vol% aqueous sulfuric acid solution for 1 minute at room temperature. Next, the evaluation substrate was immersed in a catalyst solution (10 vol% aqueous solution of metal plate activator 350, manufactured by Meltex inc.) at 30 ℃ for 5 minutes, then washed with water, immersed in a nickel plating solution (20 vol% aqueous solution of metal plate Ni-865M, manufactured by Meltex inc., pH 4.6) at 85 ℃ for 30 minutes to perform nickel plating, and then immersed in a 10 vol% aqueous solution of sulfuric acid at room temperature for 1 minute to perform water washing. Next, the evaluation sample substrate was immersed in a gold plating solution (15 vol% for AUROLECTROLESS UP and 3 vol% aqueous solution of gold potassium cyanide, pH 6, manufactured by Meltex inc.) at 95 ℃ for 40 minutes to perform electroless gold plating, and then washed with water, and further immersed in warm water at 60 ℃ for 3 minutes to perform washing with running water. The obtained evaluation sample plated with gold was attached with a transparent tape, and the state of the cured coating film at the time of peeling was confirmed. The criteria for determination are as follows.

O: no peeling.

And (delta): the edge portion was slightly peeled off.

X: peeling and whitening.

(chemical resistance to tin plating)

For the evaluation substrates prepared under the above substrate preparation conditions, plating was performed under conditions of 1 ± 0.2 μm tin using a commercially available electroless tin plating bath. In the plated evaluation substrate, the presence or absence of peeling of the protective layer and the presence or absence of immersion of the plating were evaluated, and then the presence or absence of peeling of the protective layer was evaluated by tape stripping (tape stripping). The criteria for determination are as follows.

O: no peeling.

X: peeling and whitening.

(external air)

Each of the photosensitive resin compositions of examples and comparative examples was coated on a copper foil substrate having a pattern on the entire surface by screen printing, and dried at 80 ℃ for 20 minutes. Then, the substrate was exposed to light through a photomask using an exposure apparatus equipped with a metal halide lamp, and the substrate was exposed to 1 mass% Na at a jet pressure of 0.2MPa at 30 ℃₂CO₃And developing in an aqueous solution to form a protective pattern. A powder sample was collected through the prepared protective film in a Thermal Desorption Unit (TDU) manufactured by Gerstel Company. Then, the overflowed gas component at the hot extraction temperature of (1) 150 ℃ for 10 minutes and the overflowed gas component at the hot extraction temperature of (2) 260 ℃ for 10 minutes were trapped at-60 ℃ using liquid nitrogen, respectively. The trapped overflowed gas component was separated and analyzed by a gas chromatography mass spectrometer (6890N/5973N) manufactured by Agilent Technologies Corporation, and quantified by conversion into N-dodecane, and evaluated on the following basis.

Very good: there is almost no out-gassing component.

O: little outgas was observed.

And (delta): the composition of the out-gassing was confirmed.

X: the excessive gas is abundant.

(chemical resistance)

The evaluation substrates prepared under the above substrate preparation conditions were visually observed for the state of a coating film after being immersed in a 3 wt% aqueous sodium hydroxide solution for 10 minutes, and evaluated in the following manner.

O: confirming that there was no change at all.

X: swelling or peeling of the coating film was confirmed.

(crack resistance)

Each of the photosensitive resin compositions of examples and comparative examples was applied to a substrate having a 2mm copper wire pattern formed thereon, exposed to light and developed under the same conditions as those for the production of the substrate for evaluation of electroless gold plating resistance, electroless tin plating resistance and chemical resistance, and then irradiated with ultraviolet light and cured by heat to produce an evaluation substrate having 17 protective patterns of 3mm square formed on the copper wire. The evaluation substrate was placed in a Thermal cycler for temperature cycling between-65 ℃ and 150 ℃ to perform TCT (Thermal Cycle Test). Then, the appearance was observed at 1000 cycles, and the number of cracks was counted and evaluated according to the following criteria. The denominator value "68" indicates 4 corners (4) × 17 corners of the 3mm square protective pattern, that is, the corner at 68, and the numerator value "20" or the like indicates the number of cracks generated.

◎：0/68～20/68

○：21/68～40/68

X: 41/68 or more

[ Table 1]

The amount of the dispersion containing the carboxyl resin solution and the filler solvent as the solid component

*1: carboxyl group-containing resin A-1 having aromatic Ring synthesized in Synthesis example 1 (cresol novolak starting resin CN/AA/THPAn)

*2: carboxyl group-containing resin A-2 having aromatic Ring synthesized in Synthesis example 2 (phenol-formaldehyde starting resin)

*3: carboxyl group-containing resin A-3 having aromatic Ring synthesized in Synthesis example 3 (copolymer resin)

*4: carboxyl group-containing resin (copolymer resin) having no aromatic Ring synthesized in Synthesis example 4

*5: TR-PBG-304 (manufactured by Changzhou powerful new electronic materials Co., Ltd.)

*6: irgacure OXE02 (manufactured by BASF JAPAN LTD.) (1- [ 9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl ] -1- (O-acetyloxime) ethanone)

*7: irgacure 907 (manufactured by BASF JAPAN LTD.) (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one)

*8: DPHA (manufactured by Nippon Kabushiki Kaisha) (dipentaerythritol hexaacrylate) (number of functional groups: mixture of 5-and 6-functional groups, molecular weights: 524 and 578)

*9: A-DCP (manufactured by Xinzhongcun chemical industry Co., Ltd.) (tricyclodecane dimethanol diacrylate) (2-functional, molecular weight: 304)

*10: m-350 (manufactured by Toyo Synthesis Co.) (trimethylolpropane EO-modified triacrylate) (3-functional, [ CH ]₂＝CHCO-(OC₂H₄)n-OCH₂]₃-CCH₂CH₃，n≈1)

*11: phthalocyanine blue

*12: gumei transparent yellow (クロモフタルイエロー)

*13: filler solvent Dispersion product alpha prepared in production example 1

*14: KS-66(Shin-Etsu Chemical Co., Ltd.) (polydimethylsiloxane)

*15: YX-4000 (manufactured by Mitsubishi chemical corporation) (biphenyl type epoxy resin, solid epoxy resin at 40 ℃ C.)

*16: 828 (manufactured by Mitsubishi chemical corporation) (2-functional bisphenol A epoxy resin, liquid at 20 ℃ C.)

*17: not evaluated

From the results of the examples shown in the table, it is understood that the photosensitive resin composition of the present invention is excellent in resolution, electroless gold plating resistance and electroless tin plating resistance of the cured product, and is less likely to generate outgas. In contrast, it is known that: the resolution of the comparative example, the resistance to electroless gold plating, the resistance to electroless tin plating of the cured product, and the suppression of out-gassing were inferior to those of the examples.

Further, it is understood from the results of the examples that the photosensitive resin composition of the present invention is excellent in both of chemical resistance and crack resistance.

Claims

1. A photosensitive resin composition comprising (A) a carboxyl group-containing resin having an aromatic ring, (B) a photopolymerization initiator, (C) a compound having an ethylenically unsaturated double bond, and (D) a thermosetting component, wherein the (B) photopolymerization initiator comprises a compound represented by the following general formula (1),

the thermosetting component (D) is at least one of a solid epoxy resin which is solid at 40 ℃ and a semi-solid epoxy resin which is solid at 20 ℃ and liquid at 40 ℃,

the solid epoxy resin which is solid at 40 ℃ is at least one of naphthalene type epoxy resin, dicyclopentadiene aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, novolac type epoxy resin, bixylenol phenol type epoxy resin and biphenyl type epoxy resin,

in the general formula (1), R represents a group containing an aromatic skeleton or an aliphatic skeleton, and R²Represents a hydrogen atom or an alkyl group, R³Represents an organic group containing a C3-20 cycloalkyl group, R⁴Represents a hydrogen atom, an alkyl group or an aryl group.

2. The photosensitive resin composition according to claim 1, wherein the compound (C) having an ethylenically unsaturated double bond has 2 or more ethylenically unsaturated double bonds.

3. The photosensitive resin composition according to claim 1, wherein the weight average molecular weight of the compound (C) having an ethylenically unsaturated double bond is 250 or more and less than 1500.

4. The photosensitive resin composition according to claim 1, wherein the compound (C) having an ethylenically unsaturated double bond does not have a phenolic hydroxyl group, a thiol group, and a carboxyl group.

5. The photosensitive resin composition according to any one of claims 1 to 4, which is used for forming at least any one of a solder resist and an interlayer insulating material.

6. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to any one of claims 1 to 5 to a film and drying the applied film.

7. A cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 5 or the resin layer of the dry film according to claim 6.

8. A printed wiring board comprising the cured product according to claim 7.